Railway traffic controlling apparatus



Aug. 24, 1937. J. J. VANHORN RAILWAY TRAFFIC CONTROLLING APPARATUS Original Filed April 7, 1936 R Y WW I W m m .QKH J A v a 7 mm H 3mg 5 SN NR QR? i ml Patented Aug. 24, 1593? ATENT OFFIQE RAILWAY TRAFFIC CONTROLLING APPA- RATUS application April 7, 1936, Serial No. 73,126 Renewed November 7, 1936 8 Claims.

My invention relates to railway traffic controlling apparatus, and particularly to signaling apparatus for governing the movement of traffic over stretches of track over which traffic moves in both directions.

I will describe three forms of apparatus embodying my invention, and will then point out the novel features thereof in claims.

In the accompanying drawing, Fig. 1 consti- 10 tutes a diagrammatic view showing apparatus embodying one form of my invention arranged to control signals for governing the movement of trafiic in opposite directions over a stretch of single track railroad, and employing the same line circuits for the control of the signals for both directions. Fig. 2 illustrates a modification of a portion of one of the line circuits of Fig. 1. Fig.

3 illustrates another modification of a portion of one of the line circuits of Fig. 1.

One object of my invention is the provision of a signaling system in which the signals governing trafiic in both directions are controlled over cir cuits employing but two line wires, and in which the relative polarity of the current supplied to the line circuit at one end or the other is reversed to provide three position control for the signals g for both directions. A feature of my invention is the provision, in a system of this character, of means for preventing short circuits when two current sources are connected to the opposite ends of the same line circuit in such direction that their effects are additive, by disconnecting one of said sources when this condition occurs.

Other objects and purposes of my invention will be made apparent as the description proceeds.

In order to simplify the drawing and to enable the circuits to be more readily traced, I have herein identified each switch and signal by a number and each relay by a letter or combination of letters with a distinguishing prefix identifying the switch or signal with which the relay is associated. The various relay contacts are identified by numbers and those contacts not adjacent the respective relays which operate them bear the reference characters for the respective relays as well as the numbers identifying the con-- tacts. Furthermore, instead of showing the sources of current for energizing the various line and local circuits and the wires leading thereto in detail, I have shown only the terminals of the sources which I have designated by the reference 3 characters B and C, referring to the power supply and common return terminals, respectively.

It is to be understood that in accordance with the usual practice, a separate local source of current is provided at each location.

Referring to Fig. l of the drawing, the'references i and la. designate the track rails of the main track of a single track railroad over which 5 traffic may move in either direction. The track rails are divided into sections by insulated joints 2, and each section is provided with a track circuit identified by the reference character T with distinguishing prefix. Each track circuit is pro- 10 vided with the usual track battery 3 and with a track relay identified by the reference TR with a prefix corresponding to that of the associated track section. Track switches 5 and 1 connect the main track with sidings at the two ends of 19 the stretch and the movement of traflic over these switches is governed by signals bearing the general references 6 and 8, each signal being identified by a distinguishing prefix. The head block signals R6 and L8 govern trafiic moving from left to right and from right to left, respectively, into the single track stretch and are controlled respectively by the polarized signal relays RSHR and L8HR and by the slow release repeater relays RGHP and LSI-IP. Signals R8 and L6 similarly govern the movement of trafiic out of the single track stretch, only a portion of the circuits for signals R3 and L6 are shown herein, but it is to be understood that these signals are controlled by the signal relays R8HR and LSHR and by the slow release repeater relays R8HP and LEI-IE, in a manner similar to that illustrated for signals RB and L8. It is also to be understood that the clearing of the signals and the control of traffic direction is subject to manual control from a remote point, such as a dispatchers ofiice, through the medium of a centralized trafiic control system. To illustrate such control in its relation to the present invention, three-position signal levers bearing the legend Signal and a reference number, are shown in Fig. 1 with dotted line connections to a pair of signal control relays located at each end of the stretch. Thus it is to be understood that when lever 6 is moved from its mid -position to position R or L by the dispatcher, for example, the corresponding signal control relay REES or LEI-IS becomes energized to complete the signal control circuit, subject to the usual control by tramc conditions and in accordance with the position of the track switch, to cause signal R8 or L5 to indicate caution or proceed, depending upon the condition of the next signal in advance for the same direction. Thus, for example, when relay RBHR is deenergized, signal R8 will indicate stop, and if the operator moves lever 6 to position R, relay RBI-IS will become energized and current of one relative polarity will be supplied over the line wires from back contacts of relay RBI-1P to energize relay RBI-IR in such a direction as to cause signal R6 to indicate caution. If the operator also moves lever 3 to position R to energize relays RBHS and RSHR so as to cause signal R8 to indicate caution or proceed, relay RBHP will become energized and the relative polarity of the current supplied to the line wires will be reversed, and then relay RBHR will be energized in the opposite direction to cause signal R6 to indicate proceed. Assuming relay RQHP to be deen'ergized, the circuit for relay RSHR may be traced from one terminal 13 of the source of current adjacent signal R8, back contact 9 of relay RBI-1P, back contact 25 of signal control relay LBHS, front contacts Iii and H of track relays TTR and ATTR, line wire l2, front contacts [3 and 14 of track relays AETR and TR, front contact l5 of signal control relay RGHS, the winding of signal relay Rel-IR, front contacts I6, I! and 18 of relays RBHS, 5TR and ASTR, line wire 19, front contacts 20 and 2! of relays A'ITR and lTR, back contacts 26 and 22 of relays LBHS and R8HP to the other terminal C of the same source. If now relay RBHP becomes energized, the relative polarity of the current supplied to the line wires over contacts 9 and 22 will be reversed, as is obvious from the drawing.

Since the relative polarity of the current supplied to the line circuit is reversible and since line wires i2 and L) are used for the control of the signals for both directions, it may happen that current sources may be connected at opposite ends of the same line wires in such direction that their effects are additive. To prevent the excessive flow of current when this occurs, I include a series relay A in the control circuit for one direction. Relay A, as illustrated in Fig. 1, is a double wound relay having a primary winding normally included in the line circuit which is adjusted so that relay A is non-responsive to the normal line current due to the voltage of a single source and picks up only under the double voltage condition mentioned. When relay A picks up it disconnects its primary winding and the adjacent source of current from the line circuit, and connects a secondary winding to the line circuit which is adjusted so that relay A will be held energized by the source at the distant end of the line circuit until that source is disconnected or its polarity is reversed.

Assuming now that the operator restores lever 6 to its mid-position as shown and moves lever B to position L to clear signal L8, relay LBHS will become energized and a circuit for relay L8HR will be closed from terminal B of the source of current adjacent signal R6, primary winding and contacts 23b23a of relay A, back contacts 24 and I5 of relays LSHP and RGHS, front contacts 14 and I3 of relays 5TR and A5TR, line wire 12, front contacts ll, I0 and 25 of relays ATTR, 'ITR and LBHS, relay LSI-IR, front contacts 26, 2| and 28 of relay L8HS, 'ITR and A'lTR, line wire l9, front contacts l8 and I! of relays ABTR and BTR, back contacts [6 and 21 of relays RBHS and LSHP, and contacts 28a28b of relay A to the other terminal C of the same source, so that relay L8HR will become energized to pick up relay LBIH to cause signal L8 to indicate caution. If now relay LBHP becomes energized, the polarity of the current supplied to relay LBI-IR will be reversed by the operation of contacts 24 and 21 so that signal L8 will indicate proceed.

I will now assume that levers 6 and 8 are re-' stored to the mid-position as shown, and that the apparatus assumes the condition shown in the drawing. Terminal B of the source adjacent signal R6 is now connected to line wire I2 over back contact 24, while terminal B of the source adjacent signal L8 is connected to the same line wire over back contact 9 so that the two sources are in opposition and hence no current flows in the line circuit except possibly a current of low value due to a slight difierence in the voltage of the two sources. If, however, lever 8 is now moved to position R and relay R8HP picks up, the connections of the source adjacent signal R8 will be reversed so that the voltage of the two batteries will be additive, and relay A will pick up due to the energization of its primary winding and will close contacts 2323a and 28-2811. to connect its secondary winding to line wires I2 and I9, so that relay A will remain energized, from the source adjacent signal L8, but the source adjacent signal R6 will be disconnected. Likewise, with the apparatus in the position shown in the drawing, if lever 6 is moved to the left and relay LGHP picks up, the connections of the source adjacent signal R6 will be reversed so that the voltage of the two batteries is additive, with the same result, namely, relay A will be picked up by the two sources in series and will then be held energized by the distant source, and the adjacent source will be disconnected from the line circuit until the line circult is opened or the polarity supplied at the distant end is reversed, to release relay A.

Heretofore it has been customary to employ three or four line wires for the control of polar ized line relays governing opposing signals at the opposite ends of the same stretch of track, due to the detrimental eifects of excessive battery discharge under conditions, such as those above described, which might occur if but two line wires were to be used, and it is evident, therefore, that by the practice of my invention, a considerable saving in line construction may be effected. It will also be evident that my invention is applicable to polarized circuits generally, and is not limited to the particular type of signal circuit chosen to illustrate the invention.

Since the safety of the signaling system does not depend upon the proper operation of relay A, it follows that this relay may be of a relatively inexpensive type. Relays are available in practice to which continuity contacts such as are shown in Fig. 1 can not readily be applied, but which are in other respects suitable, and in such cases the alternative form illustrated in Fig. 2 may be employed, in which the primary winding of relay A in Fig. l is replaced in the line circuit by a separate relay A2, and a second relay AS is added having a primary winding controlled by relay A2 and a secondary winding which functions in the same manner as the secondary winding of relay A in Fig. 1. The operation of the modification illustrated in Fig. 2 will be readily apparent, and it is clear from the drawing that when relay A2 picks up due to double voltage supplied by the sources at the two ends of the line circuit, contact 29 will close to energize the primary winding of relay AS, and that relay AS will then pick up to disconnect the adjacent source and to connect its secondary winding to the distant source over its own front contacts 30 and 3|.

In the event no double wound relays are available, the arrangement shown in Fig. 3 may be used, which employs only single wound relays having ordinary front and back contacts. In Fig. 3, when relay A2 picks up due to the double Voltage supplied by the sources at the two ends of the line circuit, contact 29 closes to energize the pickup circuit of a stick relay ASZ. Relay ASZ upon becoming energized, opens its back contacts 32 and 33 to disconnect the adjacent source from the line circuit and closes the corresponding front contacts to connect a line relay AP to the distant source, whereupon relay AP picks up and functions in the same manner as the secondary winding of relay A in Fig. 1, relay ASZ being held energized as long as relay AP is energized by the closing of its stick circuit including its own front contact 34 and front contact 35 of relay AP, as is obvious from the drawing.

Although I have herein shown and described only three forms of apparatus embodying my invention, it is understood that various changes and modifications may be made therein within the scope of the appended claims without departing from the spirit and scope of my invention.

Having thus described my invention, what I claim is:

1. In combination, a stretch of railway track, signals at the ends of the stretch each distinctively operated in accordance with the polarity of the current supplied thereto for governing the movement of trafiic in opposite directions through the stretch, a source of current at each end of the stretch, a reversible line circuit for the stretch for controlling the signals in accordance with traflic conditions in the stretch, switching means at each end of the stretch independently operable to connect either the adjacent signal or source of current to said line circuit at that end, means at each end of the line circuit for reversing the polarity of the current supplied thereto, a relay having a winding connected in series with the source at one end which responds only when the sources at the two ends of the line circuit are connected thereto in the additive direction, and means controlled by said relay for disconnecting the adjacent source from said line circuit as long as the other source remains connected to said line circuit in said direction.

2. In combination, a line circuit, a source of current and an electroresponsive device selectively responsive to the polarity of the current supplied thereto at each end of said line circuit, switching means at each end of said line circuit independently operable to connect either the adjacent source or electroresponsive device to said line circuit at that end, means at each end of the Y line circuit for reversing the polarity of the current supplied thereto, a relay having a winding connected in series with the source at one end, and means controlled by said relay for disconnecting the adjacent source from said line circuit when i current is supplied to the line circuit by the two sources acting in the same direction, and means for again connecting said adjacent source to the line circuit when current in said direction ceases to be supplied by the other source.

3. In combination, a line circuit, a source of current and an electroresponsive device selectively responsive to the polarity of the current supplied thereto at each end of said line circuit, switching means 'at each end of said line circuit independently operable to connect either the adjacent source or electroresponsive device to said line circuit at that end, means at each end of the line circuit for reversing the polarity of the current supplied thereto, a relay having a primary 7 5 winding connected in series with the source at one end over its own back contacts which is effective to pick up the relay only when the sources at the two ends of the line circuit are connected thereto in the additive direction, and a stick circuit for said relay including a secondary winding thereof,

its own front contacts and the source at the remote. end of the line circuit.

4. In combination, a line circuit, a source of current and an electroresponsive device selectively responsive to the polarity of the current supplied thereto at each end of said line circuit, switching means at each end of said line circuit independently operable to connect either the adjacent source or electroresponsive device to said line circuit at that end, means at each end of the line circuit for reversing the polarity of the current supplied thereto, a first relay having a winding connected in series with the source at one end which is effective to pick up the relay only when the sources at the two ends of the line circuit are connected thereto in the additive direction, a second relay having a pickup circuit including a front contact of said first relay, a stick circuit for said second relay including its own from contacts and a winding thereof and the source at the remote end of the line circuit, and means for disconnecting the first relay and the adjacent source from said line circuit when the second relay is energized.

5. In combination, a line circuit, a source of current and an electroresponsive device selectively responsive to the polarity of the current supplied thereto at each end of said line circuit, switching means at each end of said line circuit independently operable to connect either the adjacent source or electroresponsive device to said line cir cuit at that end, means at each end of the line circuit for reversing the polarity of the current supplied thereto, a first relay having a winding connected in series with the source at one end which is effective to pick up the relay only when the sources at the two ends of the line circuit are connected thereto in the additive direction, a second relay having a pickup circuit including a front contact of said first relay and a stick circuit including a front contact of a third relay, means controlled by said second relay when energize-d for disconnecting said first relay and the adjacent source from said line circuit and for connecting said third relay to said line circuit, and means including said line circuit and the source at the remote end thereof for energizing said third relay.

6. In combination, a reversible line circuit comprising two line wires, a source of current and an electro-responsive device selectively responsive to the polarity of the current supplied thereto at each end of said line circuit, switching means at each end of said line circuit independently operable to connect either the adjacent source or electro-responsive device to said line circuit at that end, means at each end of the line circuit for reversing the polarity of the current supplied thereto, a relay included in said line circuit which picks up only when the two sources are connected thereto in the additive direction, and means controlled by said relay for reducing the flow of current in said line circuit.

7. In combination, a reversible line circuit comprising two line wires, a source of current and an electro-responsive device selectively responsive to the polarity of the current supplied thereto at each end of said line circuit, switching means at each end of said line circuit independently operable to connect either the adjacent source or electro-responsive device to said line circuit at that end, means at each end of the line circuit for reversing-the polarity of the current supplied thereto, a relay having a winding connected in series with the source at one end, which relay picks up only when the sources at the two ends of the line circuit are connected thereto in the additive direction, and which is held energized as long as the source at the remote end of the line circuit remains connected thereto in said direction, and means controlled by said relay for decreasing the current in said line circuit.

8. In combination, a line circuit, an electroresponsive device selectively responsive to the polarity of the current supplied thereto at each end of said line circuit, a source of current of reversible polarity at each end of said line circuit for energizing the electro-responsive device at the other end, switching means at each end of said line circuit independently operable to connect either the adjacent source or electro-responsive device to said line circuit at that end, a relay controlled over said line circuit which picks up only when the line current is greater than that delivered by one source alone but which is held energized by line current of a substantially lower value, and means rendered effective when said relay picks up to reduce the line current to said lower value.

JAMES J. VANHORN. 

